1. Field
Apparatuses and methods consistent with exemplary embodiments relate a power receiving apparatus and a wireless power transceiving system, and more particularly, to a power receiving apparatus which may enhance power transmission efficiency by adjusting impedance generated by a parasitic inductance in a rectifier circuit which operates at high frequency and a wireless power transceiving system thereof.
2. Description of the Related Art
With the development of information and telecommunication technology, various mobile electronic products are being introduced, and thus the number of mobile electronic goods that a user is carrying around is also increasing.
Since most of these mobile electronic products operate with a battery, a method for charging the mobile electronic products is being developed. Particularly, wireless power transmission technology may provide power supply without using an electric wire by using electromagnetic resonance.
Lately, it became possible to design a resonator having 80% of efficiency for electromagnetic resonance, but the efficiency of a circuit still remains low, depressing overall efficiency of a wireless power transceiving apparatus.
Specifically, a full wave rectifier is used to rectify wirelessly transmitted power in the related art wireless power transmission method. However, in order to use electromagnetic resonance, a circuit should be operated in a MHz range. However, it is difficult to realize high transmission efficiency in the related art rectifier circuit.
More specifically, a related art rectifier circuit performs rectification using a diode. However, when the diode operates at high frequency, its impedance increases due to a parasitic component, such as, for example, parasitic inductance. As a result, high frequency AC input voltage is not rectified properly, which leads to loss and consequently, to degradation of efficiency in the wireless power transceiving apparatus.
In addition, if a load connected to the output of a rectifier circuit changes from a maximum load to a minimum load, the impedance changes due to a parasitic component and the load, and thus the scale of rectified voltage also changes. In particular, since rectified voltage increases when a load decreases in the resonance method, the burden of a DC/DC converter increases if the DC/DC converter is connected to the backend of a rectified circuit, deteriorating efficiency even further.
Accordingly, a rectifier circuit which improves efficiency of a wireless power transceiving apparatus and outputs rectified output voltage consistently even with changes in a load is needed.